On a side note, is subsidizing EVs and Hybrids really the right way to drive adoption of this technology? Only the rich can afford to buy these expensive cars (even after the tax break) which results in the middle class effectively paying for the jet-set to show off their green credentials. The market should decide which technology succeeds - and EVs will hopefully work out on their own merits.

BEV is not the only option but it is the most practical. IMHO, fuel cells are about 10 years too late. Hydrogen infrastructure is simply too expensive to build out and on-board hydrogen reformers will in all likelihood become too expensive as the US exports its natural gas and imports a significantly higher world price.

As for grid improvements, that can be done incrementally as BEV market penetration increases. A lot of this infrastructure is ageing and needs replacement or upgrading in any event. Additionally the vast majority of BEV charging occurs overnight when electricity demands are low at least for now.

I wouldn't dismiss solar so quickly as solar LCOE will hit $.08 per kWh in a few years. This converts to $2.70 an e-gallon which beats DoE target goals for hydrogen of $4.00 a gallon. Furthermore the story is not over for solar. Swanson's Law will continue to drive LCOE prices ever lower. If any of these very high efficiency panels ever come to the marketplace, one expect solar LCOE to approach a penny a kWh in due course!

Finally, BEVs are more efficient then FCEVs. I would much rather drive a fuel miser(BEV) at $2.70 a gallon then a fuel hog(FCEV) at $4.00 a gallon.

The range requirements will be highly variable from one person to another, depending on where you live, where you work, where you travel for shopping and recreation, and availability & convenience of public transportation. Consider the differences between the U.S. east coast and the western states. Distances between the places of interest in one's daily life tend to be much shorter on the east coast, public transportation is fairly extensive and "the middle of nowhere" is a faraway place you might go for a weekend getaway. But a resident of a western state, even one who works in an urban center, may have a very long commute between home & work, with limited public transportation options until he is near the city, and "the middle of nowhere" might be more a part of his regular routine -- and a place he really doesn't want to get stranded by a dead battery.

I like the idea of a fuel cell as a range extender -- renting one could be a dandy way to extend a battery or other high-power electrical energy source for long trips.

HEV with an ICE is an ugly solution, since the car has to lug around a heavy ICE whether you're using it or not, you have to run it periodically so the gasoline and other fluids don't get old, and you still have all the maintenance and emissions issues of an ICE car. A Tesla is so marvelously simple, and so reliable that car mechanics are worried about their future livelihoods. IMO, a Chevy Volt far more complex than anything I'd want to own.

"It's not just technical challenges that's holding back electric cars."

True, but perhaps you misunderstood where I'm coming from. What is holding back EVs is technical challenges, in large part, and the incessant assumption that energy storage must come from a battery.

We know the HEV pretty well by now, where H means "an internal combustion engine." That's somewhat unexciting, in my view, but is definitely doable and has no energy starvation issues. Problem is, there's still a Carnot engine in the equation.

Much more exciting are HEV designs without the heat engine, and my hopes continue to be in the fuel cell car where the hydrogen is produced on board, rather than distributed and stored as H2 gas.

Bert said: The problem is, this has always been the case with batteries. That "when" has not yet arrived, after more than 100 years.

My opinion is that this is mostly because most people stopped working on improving battery technology 100 years ago. Few advances happen by themselves -- people have to be looking at the problem, or at related problems so they notice anomalies that are key to many discoveries.

In the last 100 years scientific technology has come a long way. For example, with the Scanning Tunneling Microscope you can examine surfaces at the atomic level, something inconceivable 100 years ago. Once you have people wondering "why can't we get higher energy density?" you'll see plenty of progress with tools to analyze what's really going on. Look how far Tesla Motors has come in just 10 years.

"When batteries with 4 to 5 times the energy-density of present day batteries ..."

The problem is, this has always been the case with batteries. That "when" has not yet arrived, after more than 100 years. So other approaches should be mentioned more in the popular press, to make people aware that energy storage in a battery is not the only EV option.

Not to mention, something that keeps being overlooked, installing additional electric transmission lines is not so easy to do. Any battery storage requires upgrades to the grid, if BEVs are going to make it big time, to replace what we have now. People don't want power lines in their back yard. Powering the automotive, mass transit, and industrial fleets with batteries does increase demand appreciably, as we've discussed here before. It's hardly insignificant. And installing windmills in your backyard, and/or enough solar panels to take the load, doesn't work out too well either. So that's why in practice, especially if these BEVs will be running and will be recharged throughout the day, you do need more electrical transmission lines installed.

When batteries with 4 to 5 times the energy-density of present day batteries arrive this would imply a Tesla Model S would have a range of over 1000 miles. Except for those people with no possibility of charging overnight, would charging time be an issue since very few of us could manage to drive over a 1000 miles in the course of a day.

As for charging times themselves, a lot of R&D has gone into silicon anodes and I have read some papers that claim charging rates as high as 20C with exceptional energy density and over 5000 charging cycles before a 20% drop in charge capacity is reached.

The issue is can these anodes be mass manufactured at a competitive price?